As network data communication evolves toward increasing bandwidth, various new applications of data communication that exploit high-bandwidth connectivity are enabled. Such applications include audio and/or video teleconferencing or collaboration with ever-increasing fidelity.
For example, the use of binaural recording and playback to provide an audible sense of the position of participants in the conversation is one method for increasing audio teleconferencing fidelity. With such methods, participants in a teleconference can be “positioned” around a virtual conference table, and these synthetic participant positions facilitate determination of who is talking and/or picking out one conversation from several others. Examples of such developments can be found in U.S. Pat. Nos. 5,889,843, 5,9991,385, and 6,125,115.
However, binaural recording alone does not provide sufficient fidelity for more demanding audio collaboration applications, such as high-fidelity musical collaboration. Two further issues pertaining to high-fidelity audio collaboration are network latency and acoustic ambience. Ambience is the effect of the environment on the perception of sound. For example, song A played on radio X in a shower stall sounds very different from song A played on radio X in a concert hall. Network latency is the point to point transmission time delay induced by a network. A typical round-trip delay for present day global commodity Internet is from about 200 ms to about 500 ms, and this delay can vary significantly due to variability in network traffic and/or quality of service.
Real time audio collaboration in the presence of such large time delays is difficult, if not impossible, so special methods have been proposed for collaboration in the presence of large network latency. For example, U.S. Pat. No. 6,353,174 discusses network musical collaboration where a musical data stream is provided to multiple users, and each user is positioned at a different time within the data stream. The time separation between any two users exceeds the network latency. Each user is allowed to modify the portion of the data stream being played to that user. Although this approach eliminates the problem of conflicting modifications, it is far removed from an idealized collaboration environment which would closely mimic a conventional recording studio or other music space.
Fortunately, not all networks have as much latency as present-day commodity Internet, and in time even commodity Internet latency may decrease. For example, a Next Generation Internet (NGI) backbone link between two locations (Stanford University and Dallas) separated by about 1700 miles consistently provides a round-trip delay of about 45 ms. This time delay is dominated by propagation delay, so it will scale linearly with separation between the locations. Thus, networks having relatively short delays (especially round trip delays of 50 ms or less) can provide a wide area of coverage.
Since real time audio collaboration over such networks is not clearly ruled out by network delay, it is desirable to provide high fidelity real-time audio collaboration having a realistic ambience in the presence of as much network delay as possible. In this way, the applicability of such collaboration is maximized. However, this problem has not been considered in the art, so there is an unmet need in the art for distributed acoustic collaboration providing a realistic and shared acoustic ambience.